Measles (Rubeola) (cont.)

Edmond Hooker, MD, DrPH

Dr. Eddie Hooker is currently an Assistant Professor in the Department of Health Services Administration at Xavier University in Cincinnati, Ohio. He is also an Associate Clinical Professor in the Department of Emergency Medicine at the University of Louisville and at Wright State University. His areas of expertise include emergency medicine, epidemiology, health-services management, and public health.

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

Is it possible to prevent measles with a vaccine? How effective is the measles vaccine?

The only way to prevent measles is by receiving measles immunization: This is commonly given as a two-shot series that contains measles, mumps, and rubella vaccine (MMR) or a shot containing measles, mumps, rubella, and varicella vaccine (MMRV). The MMRV is not recommended for anyone older than 12 years of age. The current recommendation is that everyone receive two doses of the vaccine after 1 year of age. If the vaccine is received before 1 year of age, the person should receive two additional doses.

The MMR vaccine is not 100% effective, and this is why it is critical that everyone be immunized. When people are allowed to skip vaccinations, they put others at risk. This is why most states have laws requiring vaccination. Unfortunately, many states allow people to refuse vaccination based on varying criteria. Due to a sharp increase in the number of cases of measles in 2014 and 2015, there has been a renewed urgency to require everyone to get immunized.

No vaccine is 100% effective. In 2012, the Cochrane Collaboration estimated that one dose of MMR would protect prevent 92% of secondary cases (a case caused by exposure to another person with the disease), and two doses would be 95% effective. However, if most of the population is immunized (known as herd immunity), the effectiveness of the vaccine is markedly increased.

The measles vaccine is also available as a single vaccine. However, in most cases, there is no reason to utilize the measles vaccine alone without mumps and rubella vaccine. The complete schedule of recommended vaccinations is available from the CDC (http://www.cdc.gov/vaccines/schedules/index.html).

Why should people get vaccinated against measles?

Although measles was extremely rare in the United States in the 1990s and early 2000s, recently, there has been a marked increased number of cases.

When the number of vaccinated individuals starts to decrease, the disease starts to occur more frequently. This occurred from 1989 until 1991 in the U.S. During that period, there were 55,000 cases and 123 deaths from measles in the U.S. Due to a massive public-health effort, almost all children in the U.S. received measles vaccine before they were allowed to enter school. The number of cases of measles in the U.S. dropped to only 37 in 2004. At that time, most cases originated outside of the U.S. These cases came from three common sources: infants being adopted from China, U.S. travelers being exposed while out of the country (now most commonly from European travel), and from foreign travelers visiting the U.S.

However, in 2011, the number of cases grew to 222 because more people are not being vaccinated. Fortunately, there were no deaths among those 222. In 2014, the number of cases jumped dramatically to 644 cases, and there were 14 separate outbreaks. The largest outbreak was due to many unvaccinated children and adults in an Amish community in Ohio. A large multistate outbreak of measles started in December 2014 at Disneyland in California. That outbreak has continued into 2015. Most of the recent outbreaks are being traced back to individuals who refused vaccination.

Many states allow people to refuse vaccination for religious reasons (although no organized religion prohibits vaccination) and 17 states allow parents to refuse vaccinations for philosophical reasons. The only way to prevent this problem is to change laws to no longer allow refusal of vaccination except for documented allergy to vaccine components. Many states have up to 40% of preschoolers without proper vaccinations.